Bronchi (histology)

From WikiLectures

They are similar in structure to the trachea. They are formed by cartilaginous horseshoes, the so-called cartilagines bronchiales , where the right main bronchus contains 6-9 cartilages and the left 8-12. The main bronchi contain the paries membranaceus , the posterior wall of the bronchi composed of ligament and smooth muscle. Lobular bronchi have irregular horseshoe-shaped cartilages with a varied distribution around the wall, which causes a circular cross-section. The entire wall of the bronchi becomes thinner and reduced in all its layers with branching

We distinguish three layers:

  • Tunica fibromusculocartilaginea - formed by cartilage and a thin sheath of reticulate and annular smooth muscle; continues to the smallest bronchi and the beginning of the respiratory section of the lungs;
  • Tunica mucosa - is covered with epithelium and cilia; contains cells with cilia, goblet mucus cells; in the mucous membranes of the larger bronchi there are glandulae bronchiales - seromucinous sacs, which in their structure, location and function can be compared to glandulae trachealis -
  • Tunica adventitia (peribronchium) - elastic tissue around the bronchi, where vessels and nerves run allowing the movement of the bronchi during breathing; passes into the ligament in the mediastinum and into the interstitial ligament.